Canon 650-4ti owners, what computer system requirements are needed?

I've been lurking in the background (mostly) on this and other forums for the last few months and have decided to get the t4i kit to start.  The day when I can actually purchase one grows closer (barring unforeseen events). I retired last month, so income is limited.

While digesting the information from helpful people who share their knowledge many of my  questions have been answered in response to other's questions.  For this I thank all who have unknowingly helped me.

My question is what I currently have for a computer system be enough to utilize the 4ti ?

I have a PC with a 2.66 pentium processor that is maxed out with ram capacity of 2gb.  I have Windows XP, service pack 2.  I have Adobe Elements 9.  When in a store recently I discovered that the newer versions of Elements require a newer version of computer and operating system.  I also read that Lightroom 4 requires a quad-4 processor.  Lightroom 3.4 version isn't clear from what I can make of it.  It appears that older versions of photo editing software don't support newer cameras, for the most part? How about Canon's dng software, will my computer work with this program?  Digging around Canon's homepage didn't yield anything useful.  My apologies if this has been asked before, I missed it.

I also have Sagelight editor but don't see information about which camera models (4ti) is supports?  Haven't used this much, I use Fastone for quick edits, and Elements 9 for others.

So when I get a 650-4ti kit will I be able to use it with my current computer setup, or will I have to upgrade the computer and software to be able to use it?

Thanks for taking the time to read this post, and hopefully someone who knows will answer, Mike